Is there anything in Rust to convert a binary string to an integer?

Question

My binary resides as a string right now, I was hoping to format! it as an integer the same way I formatted my integer to binary: format!("{:b}", number).

I have a larger string of binary that I'm taking slices out of in a loop, so let's assume one of my slices is:

let bin_idx: &str = "01110011001";

I want to format that binary into an integer:

format!("{:i}", bin_idx);

This gives a compiler error:

error: unknown format trait `i`
 --> src/main.rs:3:21
  |
3 |     format!("{:i}", bin_idx);
  |                     ^^^^^^^

I also tried d and u and got the same error.

Answer 1

First of all, you should be using the official docs; those you pointed to are way outdated.

You have a string and you can't format a string as an integer. I think what you want is a parser. Here's a version using from_str_radix:

fn main() {
    let bin_idx = "01110011001";
    let intval = isize::from_str_radix(bin_idx, 2).unwrap();
    println!("{}", intval);
}

(playground)